odic proficiency exams. AlthoughJudge Pollak later decided to permit EB.I. fin- gerprint experts to testifY in this partic- ular case, students of forensic science felt his skepticism was justified. "We have seen forensic disciplines which focus on bite marks, hair analysis, and handwriting increasingly questioned in the courts," Robert Epstein, who had argued for the exclusion of fingerprint testimony in the case, told me. "But we have accepted fingerprinting uncritically for a hundred years." Epstein, an assistant federal public defender in Philadelphia, was responsi- ble for the first major court challenge to the discipline, in 1999, in U.S. v. Byron Mitchell. In that case, Epstein showed that standards for examiners vary widely; and that errors on proficiency tests- which are given irregularly and in a va- riety of forms-are far from rare. The critical evidence consisted of two fin- gerprint marks lifted from a car used in a robbery. To prepare for the trial, F.B .1. officials had sent the prints to agencies in all fifty states; rougWy twenty per cent failed to identifY them correctl ' ter all this time, we still have no idea how well fingerprinting really works," Ep- stein said. "The F.B.I. calls it a science. By what definition is it a science? Where are the data? Where are the studies? We know that fingerprint examiners are not always right. But are they usually right or are they sometimes right? That, I am afraid, we don't know. Are there a few people in prison who shouldn't be? Are there many? Nobody has ever bothered to try and find out. Look closely at the great discipline of fingerprinting. It's not only not a science-it should not even be admitted as evidence in an American court of law." F ingerprints have been a source of fascination for thousands of years. They were used as seals on legal con- tracts in ancient Babylonia, and have been found embossed on six-thousand- year-old Chinese earthenware and pressed onto walls in the tomb of Tutankhamun. Hundreds of years ago, the outline of a hand with etchings representing the ridge patterns on fingertips was scratched into slate rock beside Kejimkujik Lake, in Nova Scotia. For most of human history, using fingerprints to establish a person's iden- 98 THE NEW YOR.KER., MAY 27 2002 tity was unnecessary. Until the nine- teenth century, people rarely left the villages in which they were born, and it was possible to live for years with- out setting eyes on a stranger. With the rise of the Industrial Revolution, cities throughout Europe and America filled with migrants whose names and back- grounds cotÙd not be easily verified bv employers or landlords. As the sociolo- gist Simon Cole made clear in "Suspect Identities," a recent history of finger- printing, felons quickly learned to lie about their names, and the soaring rate of urban crime forced police to search for a more exacting way to determine and keep track of identities. The first such system was devised in 1883 by a Parisian police clerk named Alphonse Bertillon. His method, called anthro- pometry; relied on an elaborate set of an- atomical measurements-such as head size, length of the left middle finger, face height-and features like scars and hair and eye color to distinguish one person from another. Anthropometry proved useful, but fingerprinting, which was then coming into use in Britain, held more promise. By the eighteen- sixties, Sir William J. Herschel, a British civil servant in India, had begun to keep records of fingerprints and use them to resolve common contract disputes and petty frauds. Fingerprinting did not become in- dispensable, however, until 1869, when Britain stopped exiling criminals to Aus- tralia, and Parliament passed the Habit- ual Criminals Act. ThIs law required judges to take past offenses into account when determining the severity of a sen- tence. But in order to include prior of- fenses in an evaluation one would need to know whether the convict had a pre- vious record, and many criminals simply used a different alias each time they were arrested. The discovery that no two people had exactly the same pattern of ridge characteristics on their finger- tips seemed to offer a solution. In 1880, Dr. Henry Faulds published the first comments, in the scientific journal Na- ture, on the use of fingerprints to solve crimes. Soon afterward, Charles Dar- win's misanthropic cousin, Sir Fran- cis Galton, an anthropologist and the founder of eugenics, designed a system of numbering the ridges on the tips of fingers-now known as Galton points-which is still in use throughout the world. (Ultimately; though, he saw fingerprints as a way to classifY people by race.) Nobody is sure exactly how Mark Twain learned about fingerprints, but his novel "Pudd'nhead Wilson," pub- lished in 1894, planted them in the American imagination. The main char- acter in the book, a lawyer, earned the nickname Pudd'nhead in part be- cause he spent so much time collecting "finger-marks"-which was regarded as proof of his foolishness until he as- tounded his fellow-citizens by using the marks to solve a murder. If you were to walk into a courtroom today and listen to the testimony of a typical forensic ex- pert, you might hear a recitation much like Pudd'nhead Wilson's: Every human being carries with him from his cradle to his grave certain physical marks which do not change their character, and by which he can always be identified-and that without shade of doubt or question. These marks are his signature, his physiological au- tograph, so to speak, and this autograph can- not be counterfeited, nor can he disguise it or hide it away, nor can it become illegible by the wear and the mutations of time. . . . This signature is each man's very own. There is no duplicate of it among the swarming popula- tions of the globe! Some things have changed since Pudd'nhead Wilson, of course. A few weeks ago, I visited the headquarters